The present invention relates to applying coatings to the exterior of pipe, and more particularly to a method of foaming a synthetic plastic in place about a preformed pipe employing a tubular former which is disposed concentrically about the pipe.
It is known to apply coatings to pipes to increase the useful life of the pipes by protecting the pipes from environmental factors, and it is also known to utilize coatings to insulate pipes.
However, there are many problems associated with obtaining relatively uniform, weather resistant coatings on pipes, particularly on large diameter pipes intended to be employed in oil pipelines and similar applications. The application of exterior foam coatings to relatively large pipes is a particular problem when the pipe has been preformed and when it is necessary for the foam coating to withstand the rigorous operating conditions encountered in pipeline usages.